Brush seals also find frequent use in addition to labyrinth seals for sealing against the escape of fluids through gaps between rotors and stationary components. Brush seals in this case are particularly tolerant to a falling short of the radial clearance between the rotating component and the stationary component. The bristles of the brushes flexibly yield in the case of a falling short of the radial clearance and of a rubbing of the seal on the rotating shaft, and flexible yielding of the bristles and non-destructive wear on the bristles occur if the contact between the stationary bristles and the rotating component lasts for a longer time. In addition, a brush is well suited to absorb a pressure difference and in this way to efficiently reduce the leakiness of the seal. For overcoming larger pressure differences, brush seals, as well as labyrinth seals, are formed in a multistaged configuration so that a plurality of brushes, by arranging free spaces between the brushes, absorb a certain pressure difference until relieving to the ambient pressure. The flow direction, in the sense of the invention, in this case is the direction of the pressure decay from a high pressure level to a low pressure level, consequently the only possibility of a fluid movement in the region of the brush seal.
A brush seal arrangement is already known from European printed patent specification EP 1 271 021 B1. Such conventional arrangements have the serious disadvantage that as a result of pressure differences across the individual brushes which are simply difficult to predict, an exceptionally conservative layout has to follow and therefore for example more stages or brushes than necessary have to be provided in order to satisfy the theoretical requirements.